Abstract: This paper makes a deep analysis on the repeated tripping failures of the thrust bearing of the circulating oil slurry pump in heavy oil catalytic unit. Through collecting online monitoring data of bearing vibration and beginning with analysis on the acceleration spectrogram and envelope diagram, the paper arrives at the conclusion that the rolling element wear of the thrust bearing and the cage broken resulted from too much axial force produced by the impeller. According to the actual installation situation, the axial force on the top of the impeller is calculated quantitatively. Based on the main reasons for the thrust bearing failure, scientific treatment measures have been formulated to ensure the safe and reliable long-term operation of the circulating oil slurry pump.

Key words: heavy oil catalytic unit, circulating oil slurry pump, thrust bearing, axial force